Method for making plastic binders



April 27, 1954 c. E.- EMMER 2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Dec. 2l, 1949 4 Sheets-Sheet lfm1/*E27 far' CfzazjieEcZw/azd Emmer April 27, 1954 c. E. EMMER2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Dec. 2l, 1.949.

4 Sheets-Sheet 2 April 27, 1954 c. E. EMMER 2,676,360

METHOD FOR MAKING PLASTIC BINDERS Filed Deo. 2l, 1949 4 Sheets-Sheet 5Mfww April 27, 1954 c. E. EMMER METHOD FOR MAKING PLASTIC BINDERs FiledDeo. 2l, 1949 4 Sheets-Sheet 4 .materials in a Patented Apr. 2'?,y 1954UNITED STATES PATENT OFFICE 2,676,360 METHOD Fon MAKING PLASTIC BINDERSCharles Edward Emmer,

to General Binding a corporation of Illinois v Application December 21,1949, Serial No. 134,158

1 claim. (ci. isz-56),

This invention relates to a method for making plastic ,binders and hasas its principal object to provide such a method and apparatus arrangedto produce ,binding elements, from thermoplastic materials, free fromdefects and spoilage in a more eilicient and expeditious manner thanformerly, with little attention from the operator. of my invention is toprovide a new andY improved process for making plastic from blanks ofthermo-plastic cooling.

a new and improved process for making plastic binding elements or thelike from thermo-plastic more Vfacile and positive manner than formerlyby pre-heating the blanks and then curling the pre-heated ,blanks to asubstantially circular form, and at the same time rolling 'the blanksand softening them during the rolling operation by heat, and thensetting the blanks by cooling.

plastic material by pre-heating a plastic blank and then gripping theleading edge thereof and feeding 1t in a rotational direction and at theforming mandrel;

Figure 2 is a fragmentary view of a completed binding element; f

Figure 3 is a other parts shown in section;`

Figure 4 lis a View in side elevation of the apparatus shown in Figure 3showing the operative parts thereof in a forming position;

Figure 5 is a view in side elevation of the apparatus shown in Figure 3,but looking at the from Figure 4 and showing the parts in positionforming mandrel; and l Figure 6 is an `enlarged fragmentary detailedtransverse sectional view taken substantially along-the line VI-`VI ofFigure' 3@ 1 On the drawings: n'

Chicago, Ill., assigner Corporation, Chicago, Ill.,

Figure 1 shows a fragment of a comb-like blank lrwhich may be made froma sheet of thermoplastic material such as the vinyl chlorides orvinylacetates, known to the trade as Vnylite, or cellulose acetates,butyrates and ethylcellulose. It may also be made of various othervinylresins and from nylon compoundings, as well as any` other suitablematerials desired. The blank ||l is herein shown as having a backboneportion having a plurality of spaced relatively long nteeth |2|2extending therefrom in one direction, and short teeth 3| 3 extendingtherefromlin an opposite direction -and herein shown as being `arrangedalternately of the teeth |2| 2 so as'to extendvin the spaces between theteeth |2-|2, whenpthe blank has been curled to the form of a completebinding element M, as shown in Fige2. .Y Y. Y

, A forming mandrel I5 isshown in Figs. 3 and 5 as being, rotatablyjournaled ona vertically movable frame structure |17, consisting of twoparallel ,spaced arms IB-I, connected together lby cross members I9, |9and transversely pivoted adjacent their rear ends on the overhanging endof a transverse shaft 20, journaled on the upper ends of parallel spacedlinks 2|, 2|.vv lThe links 2|, 2| are pivoted attheirlower ends to theinsides of side walls 22f22 of the frame'23v of the machine on atransverse shaft V26.l The links 2|2| are con- 21 is pivotally mountedat itsrear end on theshaft 20, on the outside of the side wal1'22, andextends forwardly therefrom and is supported adjacent kits forward endon a l as projecting (see Figure 5). The arm 2l has an lupwardlyVopening slot 30 adapted to receive the opposite end of the mandrel I5from spaced transversely 35-35 .(see Figure 6)..v Said rollers aresuitably journaled adjacent their,v opposite ends .in the y side walls"Z2-22. fori free rotation .with respect ther-eto and are backed up attheir outer sides so as to avoid the tendency of said rolls to spreadwhen supporting the mandrel I5, by parallel spaced backing rolls 36-36extending transversely of the frame 23 and suitably journaled inopposite side walls thereof. The rolls --35 are held from downwarddeiiection by means of a transversely extending roll 39, suitablyjournaled in opposite side walls of the frame y23, and having its axisextending between the axes of the rolls 35, 35 and forming a rotatablesupport therefor.

A heating roll is rotatably mounted` at its opposite ends so its fullweight may rest on the mandrel I5 during the forming or curlingoperation in upwardly opening slots ll- 4i formed in the free endsofparallel spaced arms 153-43. The arms 43-43 are pivotally mountedadjacent their opposite -ends on upright extensions t4-44 of the sidewalls 22-22 on a transverse shaft 45. rfhe heating roll 40 is `adaptedto be supported on the forming mandrel I5 during the forming and curlingoperation and to have rolling engagement with the top sides of theplastic blank Iii and heat and roll the blank into engagement with theouter periphery of the forming mandrel I5. rfhe heating roll 45 thusserves both as a softening or heating roll and as a forming roll, toform the blank to the form of the mandrel I5, when soft. Said heatingroll may be of any well known form, and is preferably made from metal,such as iron, steel or brass and has a plurality of heating elementslll- 41 extendingr therethrough (see Figure 6). The heating elements41-41 are diagrammatically shown in Figure 6 as being electric heatingelements and are not shown or described in detail herein, since they maybe of `several well known forms.

Current is herein shown as being conducted to the heating elements 41-41by means of two spaced collector rings 49-49 mounted on a shaft 5textending outwardly from said heating roll and concentric with thecenter thereof. The collector rings 49-49 maybe engaged by brushes5I-5I, arranged to :supply current thereto, and may be suitablyinsu-lated from each other and be suitably connected to the heatingelements lil-Ali, to conduct electric current thereto.

lThe temperature of the heating -roll 40 may be controlled by atemperature-sensitive device 53, slidably engaging the top surface ofsaid heating roll, and pivotally mounted on and depending frorn alongitudinally extending vertically movable arm 54. being pivoted at itsrear end to an upright support 55, extending upwardly from a transverseplate 55, mounted on the upright extensions 44--44 of the side Walls224-22. rIhe temperature-sensitive device may be suitably connected toelectric control means (not shown) having connection with brushes 5I-5Iand collector rings IIS-49, to Vstop the flow of current to the heatingelements llL-41, when the temperature of the roll 40 becomes too high,and to supply current to said heating elementsand maintain thetemperature of said roll at a predetermined constant temperature, whichmay be capable of being set for the various forms and thicknesses ofplastic material used to make the binding elements. rEhe temperaturesensitive device 53 and the control connections therefrom to the heatingelements 41;, maybe of any well knownform and are no part of my presentinvention so are not herein shown or described in detail.

The arm 54 is shown as of the side walls ably drive the form'ng mandrelA power operated means is provided to first pivot the arms 43-43upwardly and raise the heating roll 40 out of engagement with themandrel i5 and then raise the mandrel I5 out of engagement with thesupport rolls 35--35 to permit the formed binding element to be strippedfrom the free end thereof.

The means for elevating the heating roll o and the mandrel i5 in apredetermined sequence, is herein shown as including two spaced cams 5e-5B mounted on transverse shaft 50, inwardly 22-22 of the frame 2|, andtwo spaced cams BI-GI mounted on said transverse shaft on the outer sideof the side wall 22, which in Figure 3 is the left hand side wall. rheshaft ii is suitably journaled in the side walls 22-22, and projectsbeyond opposite sides of said side walls, and has a counterweight 62, onits right hand outer end. IThe counterweight 52 is arranged toaidlifting of the heating roll 40 and mandrel I5, and to hold said roll andmandrel in elevated positions. The cams 59--59 on the transverse shaft5i) are engageable with rollers (i3- 53' mounted on and extending in-43-43, to elevate said arms upon rotation of said cams, and to permitthem to move downwardly and allow A de to come into engagement with theforming mandrel I5. The cams EI--SI on the transverse shaft 60 are outof phase with respect to the cams 5$-E9 and are engageable with camfollowers or rollers fe- 54 journaled on the sides of the arms Iii-48 ofthe frame structure I1, adjacent the side wall 22 of the frame 23 onstub shafts e-65.

It may be seen from Figures 4 and 5, that as the shaft 60 is rotating ina direction which in Figure 4 is shown as being a clockwise direction,the cams 59--59 engaging the followers 53-53 will move into position toelevate the arms 59-59 and the heating roller 40 at a relatively rapidinitial rate,v and then hold said arms and heating roller in an elevatedposition until the formed blank has been cooled and stripped from itsmandrel, and then allow said heating roll to .drop into engagement 'withsaid mandrel for the next forming operation. This will quickly removethe heating roller 4l) from the formed blank on the mandrel I5 as soonas the blank has been formed thereon, and will prevent overv-heating orinjury to the blank. After the heating roller 4Q has been fullyelevated, the cams iii- 5| will then raise the frame Ystructure I1 andthe mandrel I5 out of engagement with the support rolls 35--35 and theupwardly opening slot 30, and will hold said mandrel in position forcooling the formed blank and the stripping of the formed blanktherefrom.

The formed blank may be 'cooled when the heating roll 4I! is liftedtherefrom., by contact with the air and with the support rolls 35--35.In order to facilitate the cooling operation, however, I herein show apipe 65 spaced from and extending along the mandrel I5 and having aplurality of Aor-'iiices l-L61 opening therefrom and directed todischarge blasts of cold air on the rotating blank (see Figure 4) Amotor 69 is herein shown as being mounted on a support bracket 'inprojecting from the left :hand side wall 22,

to rotatably drive the cams 59--55 and GI-GI and also to rotatably drivethe lcams 59^-59 an'd 6I6I and also to rotat- I5. The motor B9 wellknown form, having `fa speed reducer may be an electric motorfof anypreferably of the type built therein so as to have a relative slowoutput speed. The motor69 has a drive shaft 1| the axis of which iscoaxial with the shaft 22. The shaft 1I is connected to drive thetransverse shaft 2U, journaled in the side walls 22-22 and in the framestructure I1, by means of a chain and sprocket drive 12. A sprocket 12is lkeyed to the shaft 20 drives the transverse shaft 60 through a chainand sprocket drive 14.. Another sprocket 15 is shown as being keyed onthe outer end of shaft and serves to drive a shaft 16 and the mandrel I5through a chain and sprocket drive 11. The shaft 16 projects from themandrel I5 and is Journaled in the frame structure I1, and also forms asupport for said mandrel, supporting said mandrel in overhandingrelation with respect to said frame structure. Tension is maintained onthe chain and sprocket drive 14 in all positions of y suchthat theheating roll .40 will remain in-enstantaneously move away from saidmandrel out of engagement with the formed blank. Where, however, largerbinding elements may be formed from blanks of.V greater cross-section,the speed reduction may be such, or may be capable of being changed totake care of the thicker blank so that the roller will remain inengagement with the blank during two vor more revolutions of theYblank,.plus the distances of any overlap ofthe blank. Various forms ofchange speed gearing may` be used toveifect this, whichare not hereinshown or described since they are no part of my present invention.

A stripping sleeve 19 is mounted on the mandrel l5 forvslidable movementtherealong, to strip the cooled and formed binding element from the openend thereof when the mandrel I5 has been raised above the support rolls35-v35 into the position shown in Figure 5. The stripping sleeve 19, asherein shown, has an arm 80 extending therefrom having a boss `8I at itsouter end, to which is secured a piston rod 83. The piston rod 83extends from a piston 84 movable within a cylinder 85. The cylinder 85is herein shown as being of a double acting type of Iair cylindersufficiently long to move the sleeve 19 along the entire length of themandrel I5. The cylinder 85 is supported on bracket members 86-86projecting from the free ends of the arms |8-I8 of the frame structureI1 (Figure 3).

The means for feeding each plastic blank to the mandrel I5 includes theinclined feeding with a blank receiving slot B1 extending along themandrel I5 from one end thereof to the other, and-opening to oppositeends thereof (see Figure The feeding plate 25 is adjustably supported onthe side walls 22-22 of the frame 23 on two pairs of laterally spacedlinks 88-1-88 and 89-39, pivotally supported at their lower ends ontransverse shafts Si! and 9| and extending across opposite side walls22-22. The upper ends of the links .88--88 and 89-89 are pivotallyconnected to lugs 93-93 and 94-94 respectively, depending -from thefeeding plate @if A threaded regal mcveeblein arcuate slotsrespectively, mounted inv 6. 99-99 formed in opposite side walls' 22-22of the frame 23 extends through the two links f8888 and is herein shownas having wing nuts I 00-I00 threadedon opposite ends thereof, to afforda means for holding. the feeding plate 25 in the proper relationshipwith respect to the blank receiving slot 81 for the various diameters ofmandrels which may be used to form the various binding elements desired.

A feed box |03 is mounted on and extends upwardly from the receiving endof the feeding plate 25, and is adapted to receive a stack of plasticblanks lIII-II), placed therein with the teeth I2 facing the mandrel I5.The feed box |03, as herein shownhas an adjustably moveablerear wallforming a back up plate |04. Said back up bolts I 05-| 05 having wingnuts threaded on the outer ends thereof, and slidably guided invertically spaced longitudinal slots IUS-|06, formed in side walls Il1-|01 of said feed box. The back up plate |34 is adapted to abut therear faces of the blanks I B I Il to hold them in line within the feedbox |03 and is adjustable to adapt said feed box to the various sizes ofblanks that may be used.

The meansfor ejecting the blanks Il! from the bottom of the feed box|03, one at a time is herein shown as being a pusher plate |08 slidablyguided in the bottom of said feed box and having a hand grip |09 at itsrear end. The pusher plate IEB is thus withdrawn behind the back upplate |64 to allow a blank I0 to drop the bottom of the feed plate |95,and then is moved forwardly to slidably move .the blank I0 downwardlyalong said feed plate and move the teeth I2 of said blank intoengagement with the blankreceiving slot 81 formed in the mandrel I5.

kWhile I have herein shown a manually operable pusher plate to strip thebottom blank Il) from it may readily be understood top blank of thepile. may be particularly advantageous where light weight blanks aredrel I 5, to be made into binding elements.

The feeding plate a source of electric power by electrical conducts III-IIL The heating elements IIB-III) may be of any well known form and areprovided to heat the feed plate 25 sufliciently to preheat theindividual blanks as they are fed therealong into engagement with theblank receiving condition the blank to readily follow saidmandrel beforecoming into engagement with the heating roll 40. The preheatedtemperature of forms no part of my present invention.

Aprelieatingv shoe I I2 forV the'top side of tha being fed to theforming inanslot 81 of the mandrel I5, toy

acre-seo blank I? is herein shown pivoted to laterally spaced ears I ingforwardly from the feed box L03, adjacent its lower end. Theprel'ieat'ngv shoe I I2 extends forwardly of the feed. box |03 to aposition adjacent the discharge end of the feed plate 25, and is adaptedto rest on the top surfaces of the blanks I0 as they are fed along saidfeed plate into engagement with the blank receiving slot 91. Thepreheating shoe I,I.2 is diagrammatically `shown in. Figure 6 as havingtransversely extending heating elements I,I-I I5 mounted therein andconnected to a sutable source of electric power through conductorsIIE-Ila The temperature ofthe preheating shoe IIZ` may likewise becontrolled by a suitable thermostatically operated control means, touniformly heat both sides of the blanks, and to take care of varyingthicknesses or blanks and to prevent softening of the blanks duringpreheating. The shoe II2 being free to move vertically about its axis'of connection to the lugs II3-I I3,.may thus follow each blank as it isturned upwardly by the mandrel I5 into the nip between the heating rollI6 and said mandrel.

In carrying out the process of my invention the individual blanksIIi--IIA may nrst be formed by a cutting or blanking operation. Theformed blanks may then be loaded in the feed box IES with their teethfacing the mandrel I5, and if desired or necessary may be weighted. Theymay then be ejected from, said box one at a time by the pusher plate |03into engagement with the slot 81 of the mandrel I5. During this feedingor ejecting operation each blank is preheated to a temperature to makeit readily pliable and below the softening. temperature thereof, bymeans of the heating elements. IIIl-I Ill and iI5-I I5. When the leadingend of the blank is in iull engagement with the slot 8T of the mandreli5, said mandrel may Ibe rotatably driven in a direction, which inFigure 6 is a counterclockwise direction. This will turn or move theblank I6 upwardly into engagement with the nip between said mandrel andthe heating roll 40, it being understood that said' heating roll isbrought up to the required temperature prior to the forming operation bythe heating elements iT- 4l and is maintained at this temperatureduring' the entire forming operation, which temperature should besuincient to soften the particular blank being' formed, but should notbe high enough to harm the blank. The mandrel I5 will then continue torotate and turn the blank in the nip between said mandrel and theheating, roll 40 until. it has rotated one revolution plus the initialdistance to the nip between said mandrel and heating roll and theoverlap of the teeth I3, or more than one revolution where the'thicknessof the blank demands additional heat to cause it to acquire the desiredform. After the blank has been softened to acquire the form of themandrel I5, the cam followers 63-63, will raise the heating roll 40 outof engagement with the formed blank. An air blast may then .be directedon the rotating formed blank, to cool it. When the arms 43, 43 have beenraised to their extreme elevated positions, the cams 6I-6I rotating withthe cams 56-59 will elevate the frame structure I1 about the axis of theshaft 20 and lift the mandrel I5 out oi engagement with the upwardlyopening slot 36 formed in the arm 21. The mandrel I5 may ccntinue torotate during. the lifting operation and the air blastA from the pipe 66may continue to gplay on the vrota'ting-blank, tocool'it. When-the beingtransversely I3`I I3 extendheating roll lilll and-mandrel. i5 havereachedthe upper limits of their vertical travel the blankv t0 will haveacquired, its set. The blank may then be stripped from the free end ofthe mandrel I5 in the form of a completed binding element, by theadmission of air to the head end of the cylinder effecting movement ofthe stripping sleeve 19 alongl said mandrel towards the free endthereof. The motor 69 and the shaft 66 continuing to rotate, and thecams 59 and 6I rotating therewitlnthe mandrel I5 will then vmovedownwardly into engagementfwith the supporting rolls 35-35, and theheating Vroll 40 will then move into engagement with the top surface ofsaid mandrel. The motor 69 may then be stopped with the slot 81 inalignment with. the feeding plate 25, for the insertion of a new blanktherein.`

It may be seen from the foregoing that a simple novel and improvedprocess has been provided for forming plastic binding elements fromcomblike blanks of thermo-plastic material, which contemplates feeding athoroughly preheated plastic blank into a. blank receiving or grippingslot provided in the forming mandrel I5, rotating said mandrel whilesupported on the freely rotating supporting .rolls 35i- 35, and heldinto engagement therewith by the free turning heating roller d0, andbringing the plastic blank into engagement with and. drawing it throughthe nip between said mandrel and heating roll, and compelling theplastic blank, by raising the heat thereof to a soitening temperatureupon progressive contact with said heating roll, to wrap itself aroundsaid mandreLso that after one or more complete revolutions, said plasticblank will have become sufficiently soft' to acquire the required shape.It further contemplates cooling the formed blank after completion of theforming cycle and in stripping the completed and cooled binding elementfrom the free end of the forming mandrel.

It will be understood that modifications and variations may be effectedwithout departing from the scope of the novel concepts of the presentinvention.

I claim as my invention;

In a method of forming a curled binding element from a comb-like plasticblank, the steps or" feeding the blank over a pre-heat plate to guidethe leading ends of the teeth thereof into a slotted mandrel, thetemperature of the blank being maintained :below the softeningtemperature of the plastic material thereof during the feedingoperation, rotating the mandrel about a fixed axis while pressing theblank against the mandrel with a heated roller to raise the temperatureof the blank above the softening temperature thereof, removing theheated roller from engagement with the blank, then further rotating themandrel with a cold blast of air directed against the blank, and thenstripping the formed element from the mandrel.

References Cited in the file of this patent

